If the new code is substantial, addition of subsystem-specific fault
injection might be appropriate.
+
+22: Newly-added code has been compiled with `gcc -W'. This will generate
+ lots of noise, but is good for finding bugs like "warning: comparison
+ between signed and unsigned".
+
+23: Tested after it has been merged into the -mm patchset to make sure
+ that it still works with all of the other queued patches and various
+ changes in the VM, VFS, and other subsystems.